The invention relates to the technical field of apparatuses for dispensing paper wipes made of cellulose wadding, crepe paper or suchlike materials intended more particularly for users to wipe their hands, of toilet paper.
Very many types of automatically and semiautomatically operating apparatuses for dispensing wiping materials exist and the applicant has developed several apparatuses of this type capable of dispensing strips of folded or unfolded material. These apparatuses, which give satisfactory service, are of the type comprising a moulded plastic housing accommodating in its upper part a feed reel of wiping material, a drum containing a cutter device with a serrated blade, and a presser means for feeding the strip of paper towards the drum and tensioning the paper. The cutter blade is pivoted inside the drum and moved by engagement of a fixed toothed spur connected to the pivot of the cutter blade and engaging with a fixed rack means positioned internally on one of the sides of the housing. An arrangement of this type has been described in particular in French Patent No. 2,701,016 by the Applicant. Additionally, the end of this drum is provided with a cocking mechanism with a crank and a return spring as described and illustrated in patent FR 2340887.
Nevertheless, the tractive force necessary to unwind the strip of material so that it can be cut is large, approximately one kilogram. This force may be made greater according to the quality of the materials handled, their thickness, and their presentation with or without folds, depending on the arrangement of the apparatus.
The Applicant has therefore carried out further research in order to improve still further the reliability of the apparatus and reduce the forces required of the user when he or she pulls on the strip of material.
The reduction of the tractive forces thus lead the Applicant to examine more closely the mechanism allowing the drum to rotate upon itself and enabling the cutter blade to be extended. Thus, FIG. 1 of the drawings shows a dispensing apparatus according to the prior art described in French Patent No. 2,701,016. A rack means is mounted on the drum shaft and comprises a plurality of teeth forming a rack, the first teeth being of constant profile and those which follow being of a progressive profile in order to bring about the movements of the cutter blade. In addition, the end of the blade capable of being moved towards the rack means includes a fixed part forming a spur on which a plurality of teeth form a pinion located progressively further and further away from the shaft of the blade, the leading tooth being taller in order to bring about meshing. This part forming the spur is fixed to the shaft of the blade in an eccentric position, so as to bring about the angular pivoting of the blade and of the part forming the spur. In this particular embodiment there is found to be a continuous relative positioning of approximately 90xc2x0 between the initial contact area of the mesh between the fixed rack and the spur. the pivot axis of the blade holder and the end or region of cutting of the blade about a bounded angular sector identified in FIG. 1 by the letters XOX, and having an angle (xcex1). This angle (xcex1) is constant throughout the rotation of the drum when one piece of the strip of material is being cut.
Applicant has therefore conceived of the possibility of modifying this angle in order to see whether there could be effects on the tractive force of the strip of material pulled by the user.
Surprisingly, it was found that a substantial modification of this angle by an increase in its amplitude had the result of reducing the tractive force required to pull the strip of paper, thus not inconsiderably improving the convenience of use of the apparatus.
Consequently, in a first feature of the invention, the toothed spur mechanism (8) comprises an arm (8a) which pivots counter to an elastic return means (12) relative to the blade holder, the arm defined by a curvilinear form having a plurality of teeth (8d) able to engage with the rack means (9) and defining an angle (xcex11) defined by the initial contact area of meshing between the teeth of the arm and the rack means, the pivot axis of the toothed spur and the cutting region of the blade through an angular sector YOY which is approximately 160 to 170xc2x0 .
These and still other features will become clear in the course of the description.